The present work deals with the study of efficacy of some treatments, namely soaking (in water and bicarbonate solution), ordinary and pressure cooking, germination and fermentation in reducing or removal of antinutritional factors usually present in cowpeas (protease inhibitors, tannins, phytic acid and flatus-producing oligosaccharides (raffinose and stachyose). The results showed that long-time soaking (16 h) in bicarbonate solution caused remarkable reduction in the antinutritional factors. Pressure cooking was more effective than ordinary. Cooking pregerminated cowpeas was most effective. Fermentation completely removed trypsin inhibitor, oligosaccharides and reduced remarkably phytic acid. However, tannins noticeably increased.

Tomato paste is used for color and taste of food preparations. Tomato pastes are potentially rich sources of dietary phytonutrients might contribute important health benefits to consumers. Twenty one samples from five processing steps were collected in-line processing of tomato paste (cold-break) to follow-up the changes of some quality attributes of tomato juice to paste and to investigate the relationship between some rheological properties and pectin fractions, as well as the relation between the Hunter color readings, beta-carotene and lycopene contents. The results showed that, the rheological values, pectin fractions, lycopene and beta-carotene contents were increased significantly during concentration of tomato juice to paste. Lycopene and total carotenoids contents were well correlated with Hunter color parameters ( =0.80-0.93). During concentration process, the studied rheological properties of tomato juice had positive correlations with total and pectin fractions contents. Exponential regression produced a better fit with total, oxalate soluble and water soluble pectins ( =0.83-0.94), while linear regression with acid soluble pectin content produced a good correlation ( =0.93-0.95).This investigation is useful for whom concern with tomato paste processing (cold-break).

No abstract

The effects of freezing and freeze-drying processes on the antioxidant capacity and some phytochemical contents as well as the color of pomegranate seeds were evaluated. The fresh pomegranate seeds exhibited high antioxidant activity (79.50% and 3894.73 μmol trolox/100 g dry weight, measured by DPPH and ABTS assays, respectively). The pomegranate seeds had high contents of total anthocyanins (22.80 mg/100 g), total phenolics (633.55 mg GAE/100 g) and total flavonoids (593.23 mg quercetin equivalent/100 g). Processing did not significantly affect the color attributes of the pomegranate seeds except the hue angle values. Freeze-drying process significantly decreased the antioxidant activity and phytochemicals contents of pomegranate seeds whereas freezing process had less negative effect. The total anthocyanins, total phenolic and total flavonoid contents of pomegranate seeds well correlated with their antioxidant capacity. The best correlations were between the total anthocyanins content with DPPH radical scavenging activity (R 2 = 0.9652) and ABTS•+ scavenging capacity (0.9752) values.